Last week, I followed a TFS2008 course, since we’re planning to upgrade soon (finally!). I thought I’d list the most important improvements, or better said, the improvements I liked most.
Out of the box Continuous integration
It’s unnecessary to say that this is the feature I love most in the new TFS… Previously we did our integration builds manually on commit. It’s not the same as having it automated. It requires more discipline (I’m still seeing check-ins that don’t build, or with failing unit tests…), but now those days are over. You can create a new build definition and configure it to run after each check in.
TFS also offers the following option:
Accumulate check-ins until the prior build finishes (Build no more often than every xx minutes) I’m having very mixed feelings about this option.
1) If you accumulate check-ins and build them together, it will be harder to detect what broke the build if it contains several changesets => you loose feedback and isolation of errors, while that’s one of the nicest features of continuous integration
2) If you choose to put a periodicity on your builds, that means there’s just something wrong with your build.
For both options, the conclusion is the same one: Your commit build should run very fast, and if it’s not fast enough to keep up with your check-ins, take a look at it in stead of using this option. Look at the origin of your problem, in stead of just patching it with fewer builds… You’ve now got the possibility to create several builds, make them run at different times, and based on different criteria, so use this possibility! In my opinion, I’d create an extremely fast commit build, a daily secondary build (containing integration tests and performance tests), and another daily build that deploys your application to a production-mimiced environment. You can also opt to just use one build in stead of two for the last two mentioned above, it depends on the situation and the size of your application.
New check-in policies
There’s a new build policy available that states you cannot check in unless the previous continuous integration build succeeded, and I personally think this is a valuable option. Imagine the following sequence of events:
- Developer1 checks in and a commit build is triggered
- Deverloper1’s commit build fails
- Developer2 checks in changes (that will break the build for another reason)
- Developer2’s build fails because of several reasons
I hope you can see the problem here. If Developer2 would be able to commit his changes to the repository, the build would break because of several reasons. So error-detection gets harder. And that’s where this policy becomes interesting. Only commit your changes if the previous build succeeded.
The only thing I ask myself is if TFS also prevents queued builds to run after the broken one… and also resume when the broken build is fixed… That would be a great addition to the policy!
Running unit tests without test lists
Finally we can drop the annoying VSMDI-file and tell the build to run all tests in the specified assembly. If you have several test projects you can work with wild cards to include all assemblies that end with Tests for example. This is much better than test lists, it doesn’t require any maintenance (adjusting the vsmdi-file every time you add tests) and ensures that all tests are always run. You can’t cheat anymore by excluding your failing tests from the test list to keep the build running , and that’s a good thing.
Other nice additions
You can now queue your builds, so it won’t be rejected if a co-worker checks in a second before you do. It will just be queued and will run when the previous build finishes. What’s also nice is that you can prioritize your builds. I can image that in some cases this is a valuable option.
Build retention policies
Finally you can automatically delete the build-outputs that are xx-days/weeks old, and you can even apply a different retention policy on the following levels:
- Succeeded builds
- Partially succeeded builds
- Failed builds
- Stopped builds
About partially succeeded builds by the way… I don’t think this option is very valuable. Why would you want builds that can partially succeed? A build succeeds or it fails, period. This is a black-or-white situation, grey is not a possibility. I’ve heard people defending this option by stating that a build can be partially succeeded if the solution builds but the tests don’t run, or when the solution builds, the tests run, but deployment fails…
Pfffff, all excuses. If your tests don’t run, your build fails, period. Otherwise you’re not doing continuous integration. And if you want to seperate deployment from the rest of your build, create a seperate build for it, in-stead of this option.
Version control improvements
I like the Get-latest on check-out option. I’m always reminding myself to do a get latest every time I want to check out something, so this option is very welcome. There are some developers that dislike this option because it forces you to integrate with changes your teammates made even if you don’t want to. I don’t agree. Why wouldn’t you want to integrate with other changes? You’ve got a whole test suite that’s backing you up .
There are flaws to this option though.
1) It only performs a get latest of the file your checking out. If this file is using new types or methods, you’ll be forced to do a complete get latest on project, or even solution level. If this could be automated, it would be nicer.
2) The one and only case I don’t want to integrate with the changes made is when the commit build fails.
Apart from that there have been nice UI-improvements that easen dead-simple actions a lot:
- Save attachment from workitem to disk
- Drag and drop features in the source control explorer and in workitem attachments
- Go to Windows explorer from source control explorer
- Improved help in command line (tf.exe)
TFS Power tools
The TFS power tools are a set of tools that you can download separately and use on top of TFS. And these always include very cool features. Here are the ones I appreciate the most:
It’s been available for ages with tools such as Subversion and TortoiseSVN, but now we can finally perform source control operations on our files directly from windows explorer, with TFS.
Improved search capibility using wildcards and paths, but my favourite certainly is searching by status:
- Files that are checked-out
- Files checked out to user x
Build notification application
A little monitoring application that polls the build server in search for builds that are queued, started or completed. It notifies you even if the build was started by another team-member, and displays a nice Outlook-like popup containing the build status and a direct link to it (or even the drop location).
With this nice addition you can subscribe to alerts on 3 different levels: work item, check in or build. My favourites: only getting the build-e-mail when a build fails and when a work item is assigned directly to me.